1. Field of the Invention
The present invention generally relates to a cable testing device, and more particularly to a cable testing device capable of testing a resisting conical-rotation ability of a cable.
2. The Related Art
Traditionally, in the course of a cable being in use, the cable is usually connected with a plug. When the plug is fixed in an electronic device, the cable is apt to rotate round the junction of the cable and the plug with a certain angle. The rotating orbit of the cable is conical-shaped approximately. When the cable frequently does a conical-rotation, interior conductors of the cable (such as wires, braid etc.) are apt to be broken at the junction of the cable and the plug. Thus, it is necessary to test a resisting conical-rotation ability of the cable.
Referring to FIG. 5, a traditional cable testing device adapted for testing a resisting conical-rotation ability of a cable 3′ is shown. The cable testing device includes a rotatable apparatus 1′, a clipping apparatus 2′, a driving apparatus (not shown) and a control system (not shown). The rotatable apparatus 1′ is levelly disposed on the driving apparatus controlled by the control system. The clipping apparatus 2′ is located above the rotatable apparatus 1′ for clipping one end of the cable 3′. One end of a spring 7 is connected with the cable 3′ and the other end thereof is connected to one edge of the rotatable apparatus 1′. The control system has two signal outputs respectively connected with interior conductors of the cable 3′ in series to form a circuit.
In use, the clipping apparatus 2′ is adjusted to position the cable 3′ at an angle of 45 degrees with respect to the rotatable apparatus 1′. Then the control system controls the driving apparatus to drive the rotatable apparatus 1′ and the cable 3′ to rotate periodically and reciprocally. When the interior conductors of the cable 3′ are broken, the two signal outputs of the control system are in a broken circuit so that the control system controls the driving apparatus and further controls the rotatable apparatus 1′ to stop rotating. At this moment, a result of the resisting conical-rotation ability of the cable 3′ can be gotten according to the rotating times of the rotatable apparatus 1′ shown on the control system.
The foregoing cable testing device tests the resisting conical-rotation ability of the cable 3′ by way of the spring 7 connecting with the cable 3′ and the rotatable apparatus 1′ so as to produce a pulling force acting on the cable 3′. However, when the rotatable apparatus 1′ accelerates or decelerates in the process of rotating, the pulling force is apt to be changed. Furthermore, after the spring 7 and the cable 3′ rotate periodically and reciprocally for a long time, the spring 7 and the cable 3′ are apt to fatigue to result in the length thereof lengthening, thereby the pulling force acting on the cable 3′ is reduced. Therefore, the result gotten by the above-mentioned cable testing device is not accurate enough.